JPH0242698B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a DC power supply device for relieving a voltage drop in the feeding voltage of an electric railway using a DC feeding system.

[Prior art]

In electric railways that use the DC feeding system, rectifier substations have traditionally been installed at intervals of several kilometers to about 10 kilometers, and large-capacity substations receive power at a special voltage of 20KV or more, and the specified DC voltage is It is converted into power and supplied to the overhead lines.

However, if there is no special high-voltage power supply line near the substation installation site, special high-voltage power supply equipment must be installed over a long distance to the substation location, and the cost of installing a rectifier substation, including the cost of the power supply equipment, will increase. The cost of equipment for this purpose became extremely high. On the other hand, if a rectifier substation is installed in a location where it is easy to obtain extra high-voltage power as a countermeasure, the distance between the rectifier substations may become extremely long, and the DC overhead line voltage at the midpoint of the substation or the end point of one-way transmission may drop abnormally when the vehicle is running. I had a problem.

[Summary of the invention]

This invention is intended to solve this problem, and is capable of effectively relieving voltage drops at midpoints of substations without installing special high-voltage power supply equipment over long distances, and rectifier equipment used there. The present invention provides a DC power supply device that can reduce capacity.

[Embodiments of the invention]

FIG. 1 is a diagram of the device on which the invention is based.
In the figure, 1 is a main substation composed of a rectifier 11 and a transformer 12, and a power receiving line 13 receives power at an extra high voltage such as 60 KV. 2 is a feeder line and trolley wire, 3 is a rail, 4 is a vehicle, 5 is a feeding voltage compensator according to the present invention, 6 is a storage battery, 7 is a thyristor switch circuit having thyristor switches 71 to 74 and 75 to 78, and 8 is a Smooth reactor 8
0, a rectifier composed of thyristors 81 to 86, a transformer 87, and an AC circuit breaker 88, and a power receiving line 89 receives power at a high voltage such as 6KV. 91 is a mechanical or thyristor-type high-speed shield disconnector, 9
2,93 is a disconnector.

Next, the operation will be explained. First, when the thyristor switches 72 and 73 are turned off, the current flows from the rail 3 to the disconnector 93 to the thyristor switch 73 to the rectifier 8 to the thyristor switch 72.
→Storage battery 6→High speed disconnector 91→Disconnector 92→
The current can flow in the direction of discharging the storage battery 6 along the path of the feeding line 2, and by controlling the voltage of the rectifier 8, the output of the feeding voltage compensator 5 can be controlled at a constant voltage with a current limiting function, etc. .

In addition, when the thyristor switches 71 and 74 are turned on, the current flows through the feeder wire and trolley wire 2 → disconnector 92 → high-speed shield disconnector 91 → storage battery 6 → thyristor switch 71 → rectifier 8 → thyristor switch 74 → disconnection. The flow can flow in the direction of charging the battery 6 through the path from the device 93 to the rail 3, and by controlling the voltage of the rectifier 8, the charging current can be controlled at a constant current value to a desired current value, and in order to prevent overcharging of the storage battery 6. It is possible to provide a voltage limiting function for the six terminal voltage of the storage battery.

The effects of this configuration will be explained below.

The rated voltage of feeder line 2 is 1500V, and the main substation 1
Its capacity is 1500KW, and its voltage-current characteristics are as follows.

Ess＝Ed ₀ −RssIss＝1620V−0.12ΩIss ……(1) Formula Here, Ess: Main substation voltage Iss: Main substation current Ed ₀ : Main substation no-load voltage Rss: Main substation equivalent resistance The distance between the substation 1 and the feeding voltage compensator 5 according to the present invention is 15 km, and the contact wire resistance (total resistance of feeder wire, trolley wire, rail, etc.) is 0.04.
Ω/Km, and the peak value of the vehicle current is 1000A, and the characteristics of the feeding voltage compensator 5 according to the present invention _are as follows:
Below 300A, the voltage E _B is constant at 1150V and the current I _B is
We will consider an operation in which the voltage E _B is not limited to 1150 V after reaching 300 A, that is, a case of constant voltage control with a current limiting function.

This characteristic is illustrated in the upper right corner of Figure 2.
Since the rectifier 8 is composed of a thyristor bridge, it is possible to perform not only a forward converter operation that outputs a voltage in the positive direction, but also an inverse converter operation that outputs a voltage in the negative direction, so that control is possible in a wide range. .

Now, the position of the vehicle 4 is determined by the distance x from the main substation 1.
Km, and assuming that 1000 A is flowing at that point, when using the device shown in Fig. 1, if there is no voltage compensator 5, the pantograph point voltage E _P of the vehicle 4
is the value shown by the dashed line in the graph of FIG. In other words, the farthest point from main substation 1 (x=15Km
The voltage at point ) will drop to 900V.

Therefore, the feeding voltage compensator shown in Fig. 1 is
If it is installed at the point Km, the voltage at the panda point of vehicle 4 is
E _P has the value shown by the solid line in the graph of Figure 2, and a good vehicle panda point voltage can be obtained on the entire line. Also, as the feeding voltage compensator 5, 1150VDC x 300A =
As mentioned earlier, the output capacity is 345KW.
For example, it can receive power at high voltage such as 6KV,
It can be seen that it is economical and has a high installation effect. Conversely, when charging a storage battery, the charging current is usually about 1/10 or less of the discharging current, so the impact on the overhead contact line is small.

Here, we have described the case of one-sided power feeding from main substation 1, but this corresponds to the case of branch lines branching from the main line, and even when considering between two main substations, it is the first The device shown in the figure can be applied.

Next, switching control of the thyristor switch circuit 7 will be considered.

From the state where the thyristor switches 71 and 74 are on (charging state), the thyristor switch 7
2 and 73 are on (discharging state), first turn off the gates of thyristor switches 71 and 74, then turn off the mechanical or thyristor type high speed circuit breaker 91, and then start charging. the current
By setting it to 0A, thyristor switch 71,
After turning off the thyristor switches 74, the high speed breaker 91 is turned on and the gates of the thyristor switches 72 and 73 are turned on to turn them on. Switching from the discharging state to the charging state can also be performed in a similar manner. Since this switching method requires a high frequency of opening and closing of the high-speed disconnector 91, a thyristor-type non-contact switch or disconnector is useful, but a mechanical switch has limitations on mechanical life.

Therefore, in the device shown in FIG. 1, the charging/discharging direction of the thyristor switch 7 is switched without opening/closing the high-speed breaker 91.

Figure 3 shows the thyristor switch 7 from the charging state.
1, 74 is a simplified circuit connection diagram showing a method of turning off the circuit 1, the solid line current indicates a charging current, and the same reference numerals as in FIG. 1 indicate the same parts.

As is clear from Fig. 3, the thyristors 81 to 8
When the thyristor bridge constituted by 6 performs an inverse converter operation and narrows the charging current to 0A, the thyristor switches 71 and 74 can be easily turned off by turning off the gates.

In other words, constants are set so that the following relationship holds between the no-load voltage Ed ₀ of the main substation 1, the storage battery voltage E _BD when it is about to be discharged, and the maximum reverse conversion operating voltage E _DR of the rectifier 8. Setting and phase control of the rectifier 8 are sufficient.

E _DR ＞Ed ₀ −E _BD ...Formula (2) The same method can be used to turn off the thyristor switches 72 and 73 from the discharge state. The following relationship should be established between the point voltage E _P , the storage battery voltage E _BC at the time of charging, and the maximum inverter operating voltage E _DR of the rectifier 8. The solid line current in FIG. 4 indicates the discharge current, and the same symbols as in FIG. 1 indicate the same parts.

E _DR ＞E _BC −E _P ...Equation (3) According to this method, the high-speed shunt breaker 91 can be used as a shunt disconnector in the event of an accident while being always on, and the thyristor switches 71 to 74 can be Rectifier 8
can be turned off by reverse conversion operation using phase control, so switching between charging and discharging states can be performed smoothly. However, in order to satisfy equations (2) and (3) above, the installed capacity of rectifier 8 is correspondingly large. It may happen.

This invention was made in view of these problems, and it is possible to effectively relieve the voltage drop at the intermediate point of a substation without installing special high-voltage power supply equipment over a long distance, and to reduce the rectifier equipment capacity. The purpose of the present invention is to provide a DC power supply device that can reduce the

5 to 7 show embodiments of the present invention, and the first
Instead of turning off the thyristor switching circuit by controlling the rectifier as in the device shown,
At least one of the thyristor switches of the thyristor switching circuit is a thyristor switch with a forced commutation circuit. That is, in FIG. 5, a thyristor switch 71 with a forced commutation circuit having a current breaking capability is used, and the same reference numerals as in FIG. 1 indicate the same or corresponding parts. In the circuit shown in FIG. 5, it is not necessary to satisfy the condition of equation (2) above in order to turn off the thyristor switches 71 and 74 from the charged state, so there is no need to increase the inverse conversion operating voltage of the rectifier 8. The installed capacity of the rectifier 8 can be reduced. This is particularly useful when the output voltage of the rectifier 8 is determined predominantly by the above equation (2).

Similarly, if the output voltage of the rectifier 8 is determined predominantly by the above equation (3), the thyristor switch 73 should be a thyristor switch with a forced commutation circuit that has the ability to cut current and cut off the current, as shown in FIG. is useful, and if the above equations (2) and (3) are equally dominant, then the thyristor switch 7 as shown in FIG.
It is useful to use thyristor switches 1 and 73 with forced commutation circuits having the ability to both supply and interrupt current.

〔Effect of the invention〕

As described above, the feeding voltage compensator according to the present invention has an excellent feeding voltage drop compensation function and requires only a small output capacity, so it does not require a special high-voltage power receiving system like a main substation, Since the device can be driven by receiving power, there are fewer restrictions on installation, and switching between charging and discharging states can be performed smoothly.In addition, it is possible to force a part of the thyristor switch that conducts the charging and discharging current of the storage battery. By using a thyristor switch with a commutation circuit, practical effects can be achieved, such as reducing the capacity of the rectifier equipment.

[Brief explanation of the drawing]

Figure 1 is a circuit configuration diagram of the device that is the basis of the present invention, Figure 2 is a characteristic diagram for explaining its effects,
3 and 4 are simplified circuit connection diagrams for turning off the thyristor switch from the storage battery charging/discharging state, and FIGS. 5 to 7 are circuit connection diagrams showing the main parts of the embodiment of the present invention. . Note that the same reference numerals in the figures indicate the same or equivalent parts. In the figure, 5...Feeding voltage compensator, 6...Storage battery, 7...Thyristor switch circuit, 71-74
...Thyristor switch, 8...Thyristor rectifier.

Claims (1)

[Claims] 1. A thyristor switch circuit in which two sets of electrical circuits in which first and second thyristor switches are connected in series are connected in parallel, one electrical circuit of this thyristor switch circuit is connected to the connecting electrical circuit of the first and second thyristor switches, A storage battery having a current capacity capable of passing the required current to be sent to the feeder line, a rectifier connected between the terminals of the thyristor switch circuit and capable of controlling the supply of current corresponding to the charging current and discharging current of the storage battery, The other end of the storage battery and the connection point of the first and second thyristor switches of the other electric path of the thyristor switch circuit are connected to a power supply path, and the thyristor switch circuit connects a thyristor to which a charging current or a discharging current is passed. A feeding voltage compensator for electric railways, characterized in that at least one of the switches is a thyristor switch with a forced commutation circuit.